Shortcut digital signature verification failure

[Steven M. Bellovin]

In message <20020621162638.A822154 at exeter.ac.uk>, Adam Back writes:
>Doesn't a standard digital signature plus hashcash / client puzzles
>achieve this effect?
>
>The hashcash could be used to make the client to consume more cpu than
>the server.  The hashcash collision wouldn't particularly have to be
>related to the signature, as the collision would just act as a
>proof-of-work entitling the client to have the server verify the
>accompanying signature.
>

That involves extra round trips, and as such isn't suitable for all 
uses.

		--Steve Bellovin, http://www.research.att.com/~smb (me)
		http://www.wilyhacker.com ("Firewalls" book)



---------------------------------------------------------------------
The Cryptography Mailing List
Unsubscribe by sending "unsubscribe cryptography" to majordomo at wasabisystems.com